﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Reflection;

using System.Collections;
using System.Data;

/// <summary>
///ConverToDataTable 的摘要说明
/// </summary>
public class ConverToDataTable
{

    #region 数据集互操作
    /// <summary>
    /// 将集合类转换成DataTable
    /// </summary>
    /// <param name="list">集合</param>
    /// <returns></returns>
    public static DataTable ToDataTable(IList list)
    {
        DataTable result = new DataTable();
        if (list.Count > 0)
        {
            PropertyInfo[] propertys = list[0].GetType().GetProperties();
            foreach (PropertyInfo pi in propertys)
            {
                result.Columns.Add(pi.Name, pi.PropertyType);
            }

            for (int i = 0; i < list.Count; i++)
            {
                ArrayList tempList = new ArrayList();
                foreach (PropertyInfo pi in propertys)
                {
                    object obj = pi.GetValue(list[i], null);
                    tempList.Add(obj);
                }
                object[] array = tempList.ToArray();
                result.LoadDataRow(array, true);
            }
        }
        return result;
    }

    /// <summary>
    /// 将泛型集合类转换成DataTable
    /// </summary>
    /// <typeparam name="T">集合项类型</typeparam>
    /// <param name="list">集合</param>
    /// <returns>数据集(表)</returns>
    public static DataTable ToDataTable<T>(IList<T> list)
    {
        return ToDataTable<T>(list, null);
    }

    /// <summary>
    /// 将泛型集合类转换成DataTable
    /// </summary>
    /// <typeparam name="T">集合项类型</typeparam>
    /// <param name="list">集合</param>
    /// <param name="propertyName">需要返回的列的列名</param>
    /// <returns>数据集(表)</returns>
    public static DataTable ToDataTable<T>(IList<T> list, params string[] propertyName)
    {
        List<string> propertyNameList = new List<string>();
        if (propertyName != null)
            propertyNameList.AddRange(propertyName);

        DataTable result = new DataTable();
        if (list.Count > 0)
        {
            PropertyInfo[] propertys = list[0].GetType().GetProperties();
            foreach (PropertyInfo pi in propertys)
            {
                if (propertyNameList.Count == 0)
                {
                    result.Columns.Add(pi.Name, pi.PropertyType);
                }
                else
                {
                    if (propertyNameList.Contains(pi.Name))
                        result.Columns.Add(pi.Name, pi.PropertyType);
                }
            }

            for (int i = 0; i < list.Count; i++)
            {
                ArrayList tempList = new ArrayList();
                foreach (PropertyInfo pi in propertys)
                {
                    if (propertyNameList.Count == 0)
                    {
                        object obj = pi.GetValue(list[i], null);
                        tempList.Add(obj);
                    }
                    else
                    {
                        if (propertyNameList.Contains(pi.Name))
                        {
                            object obj = pi.GetValue(list[i], null);
                            tempList.Add(obj);
                        }
                    }
                }
                object[] array = tempList.ToArray();
                result.LoadDataRow(array, true);
            }
        }
        return result;
    }

    public static DataTable Serialize<T>(List<T> lstSource)
    {
        DataTable dtSerialize = new DataTable();

        // column names 
        PropertyInfo[] oProps = null;

        if (lstSource == null) return dtSerialize;

        foreach (T rec in lstSource)
        {
            if (oProps == null)
            {
                oProps = ((Type)rec.GetType()).GetProperties();
                foreach (PropertyInfo pi in oProps)
                {
                    Type colType = pi.PropertyType;

                    if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition() == typeof(Nullable<>)))
                    {   //判断是否为 System.Nullable 类型
                        colType = colType.GetGenericArguments()[0];
                    }
                    dtSerialize.Columns.Add(new DataColumn(pi.Name, colType));
                }
            }

            DataRow dr = dtSerialize.NewRow();
            foreach (PropertyInfo pi in oProps)
            {
                dr[pi.Name] = (pi.GetValue(rec, null) == null ? DBNull.Value : pi.GetValue(rec, null));
            }
            dtSerialize.Rows.Add(dr);
        }
        return dtSerialize;
    }


    #endregion
}

	
